The present work aims to study the relationship between some physico-chemical parameters and both planktonic and epiphytic microinvertebrates associated with the floating plant Eichhornia crassipes in River Nile at Qanater region. Water samples,  planktonic and epiphytic microinvertebrates were collected seasonally from eight sites in the investigated region. The results indicated that the maximum occurrence of planktonicinvertebrates (810 org./L) was recorded during Winter. Rotifera formed the highest percentage of zooplankton (96.77 %), followed by Copepoda (1.88 %) and Cladocera (1.10 %). Meroplankton and Protozoa formed the lowest dominant groups. Thirty seven planktonicspecies were recorded belonging to Rotifera (30 species), Cladocera (2 species), Copepoda (1 species), Protozoa (2 species) and Meroplankton (2 species). On the other hand, the maximum occurrence of epiphytic invertebrates (1612100 org./m² plant) was recorded during spring. Forty five species were recorded belonging to Rotifera (27 species), Protozoa (5 species), Cladocera (9 species),  Copepoda (2 species) and Oligochaeta (2 species).
The epiphytic microinvertebrates associated with the floating plant Eichhornia crassipes in River Nile at Qanater region recorded the highest number of species and groups than planktonic invertebrates. This indicates that the aquatic plant Eichhornia crassipes habitats are more diverse and have high species richness. The principal component analysis (PCA) was conducted between physico-chemical parameters and planktonic and microinvertebrates.